A report by Shaena Montanari for Forbes.
Once upon a time I thought I could be a marine biologist—at least until I took my first scuba diving course in college for my physical education requirement. It was clear diving did not come easily to me as I buckled under the weight of the tanks and struggled with my mask on the bottom of the school swimming pool watching used band-aids float by. At the end of the course after a lackluster certification dive, I decided it wasn’t for me and I resigned myself to a life on a land as a paleontologist. After all, fossils are in rocks and rocks are on dry land, right?
Yes and no. While fossil hunting conjures up images of dusty deserts and dinosaur skulls in the Gobi Desert, there is a whole untapped world of bones most of us don’t seek, and it is underwater. And in caves. That’s right, “underwater cave paleontologist” is a real job.
Cave diving is a notoriously difficult pursuit, but the allure is undeniable. Crystal clear water full of otherworldly rock formations draws divers in to caves, sometimes to their demise. It is easy to get lost in a cave, run out of air, or kick up silt and be completely unable to escape to the surface. Zachary Klukkert, a PhD candidate at the City University of New York Graduate Center, was drawn in by the combination of fossils and diving, making him a rare sort indeed. I talked with him about the training, hardships and joys about being a paleontologist who works underwater.
It may be hard to imagine in this age of rising sea levels, but when the climate was cooler and more ice covered the planet during the Pleistocene (from about 2.5 million to 10,000 years ago), lower sea level increased the amount of land above water animals could live on. As sea levels rose when ice melted, the ocean reclaimed this turf and now these sites are underwater. Caves provide a great hideout for mammals and other critters looking for cover—they also provide an undisturbed resting place for their bones when it floods.
This work not only takes place underwater, but also mostly in the Caribbean where easily dissolved limestone forms networks of caves and sinkholes. I asked Klukkert why these caves are so fascinating to explore, and it is clear he views it as sort of a 2-for-1 adventure: “I take in and admire the majesty of the environment that I am visiting. Every turn is potentially a new world, in some cases a room or passage never seen before by human eyes. I contemplate the processes that lead to the features I see, and how changing water levels influenced the taphonomy of the site. It’s really an incredible experience every time I enter a site, whether or not I find remains to take back to the museum for study.” The above video made by the Dominican Republic Speleological Society, one of Klukkert’s collaborators on the project, gives a taste into what cave diving for fossils in the Caribbean is like.
As an evolutionary primatologist, Klukkert is mainly interested in exploring submerged caves in the Dominican Republic to find recently-extinct New World monkeys (like this one from his academic supervisor Alfred Rosenberger). There were big changes to the biodiversity of New World primates relatively recently in geologic terms, and he wants to find out why. “The diversity (and change) of species of small mammals can be very useful for testing theories about the cause of major faunal turnovers. In this case, two common hypotheses for the collapse of Caribbean mammalian diversity are, 1) the arrival of humans (i.e. as in Madagascar), and 2) local climate changes in advance of human occupation.”
Klukkert’s supervisor Alfred Rosenberger is the one in charge of this operation called Project Antillothrix, along with Phillip Lehman of the Dominican Republic Speleological Society and Renato Rímoli from Museo del Hombre Dominicano. They are not just interested in primates, but reconstructing the extinct animal community as a whole. The team has uncovered incredibly complete remains of sloths and crocodiles hinting at the lost biodiversity of the islands.
Keen on becoming an underwater paleontologist? It isn’t a skill you pick up overnight, says Klukkert, as cave diving requires advanced training beyond just open water skills. “A submerged cave is about as inhospitable as anywhere on the planet to humans. Learning how to survive in this alien world means pushing yourself to turn off perfectly rational, hard-wired fear and panic responses, and this can be extremely unpleasant, at times, though ultimately can also be a lot of fun,” Klukkert says, adding “cave training involves a lot time practicing skills while blindfolded, underwater, while someone is pretending to be panicking and grabbing for your breathing gas.”
As one of the few paleontologists who does field work underwater, Klukkert knows the dangers but wants to keep exploring, because if he does, he will keep making new discoveries in these unchartered waters. “It does add some additional risks, but knowing the wonders that the fossils in the caves may hold in addition to the beauty and almost religious experience of being in the cave, only makes this type of work more exciting and it’s worth the extra preparation and precautions.”